A dislocation may damage adjoining nerves, muscles, and blood vessels and impair their function. The popliteal artery, which carries the entire blood supply to your lower leg and foot, can be injured or pinched shut. This is a medical emergency and requires urgent evaluation and diagnosis. The symptoms are pain, the lower leg may turn pale and cold, have poor or no pulse, and the leg may swell.

Nerves to your lower leg can be cut or injured, causing your lower leg to become numb (paresthesia), weak (paresis),
or paralyzed.

Blood clots tend to form during the period ("post-op" or "post-operatively") when you cannot move following a knee replacement.

Clots become progressively less common with time.

A clot in your vein generally causes new pain, swelling, or redness in your lower leg.

The greatest concern is that the clot will travel through your veins and could lodge in your lung (pulmonary embolism).